I initiated the upgrade last night and let it run while I was sleeping. This morning I got up and found that it ran in to some problems. I noticed that some things were already upgraded - namely, Firefox was upgraded from 3.0 to 3.5. However, the upgrade could not complete and I had no choice but to cancel it and reboot the computer.

Much to my dismay, I could not even boot back in to Kubuntu. Fortunately my Windows partition could still boot and run fine. After much searching and experimenting, I finally solved the problem, thanks to this thread:Nabble - kubuntu-users - URGENT: Problem with mounting

I had to:

boot a live CD (running Kubuntu 9.04)

mount the hard drive partition running my installation of Kubuntu

repair the boot loader so that it would boot the new version (9.10 Karmic) instead of the old version (9.04 Jaunty).

run the dpkg command to finish the upgrade

Fortunately that all worked and I am now running the new version, Kubuntu 9.10.

There are a couple of things to watch out for during any upgrade of the version of Ubuntu:

Any third-party repositories listed in /etc/apt/sources.list will be disabled. They have to be manually un-commented out again. It could also happen to repositories listed in the /etc/apt/sources.list.d/ directory. The upgrade process will inform you that it is doing this - it gives you fair enough warning, you just have to remember that it happened.

Several configuration files will be modified. If the upgrade process detects that any of them has customizations or changes, it will ask for a decision on how to handle it. Fortunately while upgrading to this release, I only had one instance of this happening (with the file /etc/kde4/kdm/kdmrc). Normally I make a backup copy of the file, and then tell the upgrade process to use the version that comes with the new release. Then I compare the differences between the old (customized) version of the file, and the new one that it is using. If there are any significant changes that I want to retain, I put those back in manually.

Aside from some minor warnings and notifications that popped up, it appeared that everything was functioning normally. The only problem was audio did not work in every application. Music played in Amarok, but no sound was audible from VLC or Flash.

Lastly, there were a few cosmetic things I wanted to change, just as a matter of personal preference:

Broken icons in Kickoff Start Menu: Right-click the K icon, choose Menu Editor, select the application, and click on the icon image to select a new one, save and quit. If the application is in the list of favorites in the start menu, open the start menu, right-click on the application, and do Add to Favorites again. Likewise if the application is in the task manager panel, removing the shortcut and re-adding it will repair the icon.

Change the desktop theme from the new Air theme back to the previous Oxygen theme: Right-click on the desktop, choose Desktop Settings, and set Desktop Theme.

The last thing I want to do is replace the default theme in Firefox with a new one that matches KDE. This one works for Firefox 3.0 but is not compatible with Firefox 3.5 yet.Kde4 + Firefox3 :: Add-ons for Firefox

The whole process took longer than I had hoped, but I'm happy to be on the new version of Kubuntu 9.10 with everything running smoothly.